1. Field of the Invention
The present invention relates to an information recording medium, and a method and an apparatus for recording information into the medium. The present invention also relates to a method and an apparatus for reproducing information recorded in the information recording medium. More particularly, the present invention relates to an information recording medium in which a lead-in area and an over-run protection area, both including an area which records chain volume management information for obtaining the end position of an accessible area, and which has a file structure in which a specific virtual address is assigned to a specific file structure, and a method and an apparatus for recording information into the information recording medium.
2. Description of the Related Art
Recently, various types of media have been used for recording digital data. Among other things, a DVD-R disk is becoming the focus of attention as an inexpensive optical disk having a large capacity. The writing or reading operation of the DVD-R disk will be described below with reference to FIGS. 13 through 18. In the following description, a descriptor, a pointer, and the like, which are recorded as volume file structure, are in conformity with ISO/IEC 13346 standards or universal disk format (UDF) standards unless otherwise specified.
In brief, the description is as follows. Initially, a data structure diagram of an information recording medium shown in FIG. 13 and a block structure diagram of an information recording/reproducing apparatus shown in FIG. 15 will be described.
Next, a data structure diagram of the information recording medium after a closing process shown in FIG. 18 will be described with reference to a flowchart of a closing process shown in FIG. 17.
Finally, the operation of the information recording/reproducing apparatus when reproducing a file will be described with reference to FIG. 15 and a flowchart of a reproduction process in the information recording/reproducing apparatus shown in FIG. 19.
In FIG. 13, a conventional information recording medium 1300 is shown. The information recording medium 1300 is, for example, one which is in conformity with DVD-R physical standards (version 1.0). For example, a file is recorded in the information recording medium 1300 using a volume file structure in conformity with DVD-R file system standards (version 1.0).
FIG. 14 shows a directory structure. A file recorded in the information recording medium 1300 are managed in accordance with the directory structure of FIG. 14.
In FIG. 13, a lead-in area 108 including a physical format information area 1332 is provided at the head of a data recording area in the information recording medium 1300. Following the lead-in area 108, a volume space 104 is provided.
In a formatting process, in the volume space 104, a volume structure area 118, a file structure/file area 120, and a virtual allocation table (VAT) structure area 1322 are created. A volume structure area 118 which stores a volume structure is provided at the head of the volume space 104.
Further, upon recording an AVfile which is managed in accordance with the directory structure of FIG. 14, a file structure/file area 124 and a VAT structure area 1326 are created.
Next, in a closing process which enables the information reproducing apparatus incapable of detecting a position in an unrecorded area to search the current volume file structure while prohibiting access to an unrecorded area, a border-out area 1310 and a physical format information area 1332 are created in a data recording area 102. The border-out area 1310 includes a state determination area 1334. The physical format information area 1332 is provided in the lead-in area 108 which is unrecorded after the formatting process. The details of the conventional closing process procedure will be described later.
Further, upon recording a Datafile, which is managed in accordance with the directory structure of FIG. 14, a file structure/file area 128 and a VAT structure area 1330 are created in the volume space 104.
Finally, by executing the closing process again, a border-out area 1312, a state determination area 1334, and a border-in area 1311 are created in the volume space 104. The border-out area 1312 includes a state determination area 1336 which is unrecorded. The state determination area 1334 provided in the border-out area 1310 and the border-in area 1311 including a physical format information area 1335 are recorded in the volume space 104.
Every time the closing process is executed, a logical zone, in which a volume file structure and a file are recorded, is created in the volume space 104. In the volume space 104, the logical zone is positioned between the lead-in area 108 or a border-in area and a border-out area.
A detailed data structure of physical format information will be described below with reference to FIG. 13. The physical format information includes the address information of a logical zone, the address information of a border-out area, and the address information of a border-in area which are used to manage such a zone and areas provided in the information recording medium 1300.
Since the border-in area 1311 is created from the head of an unrecorded area 138, the physical format information recorded in the physical format information area 1335 includes the address information of the unrecorded area 138 as the address information of the border-in area 1311.
Further, the address information of a border-out area included in the physical format information and the address information of an unrecorded area are utilized so as to prevent a reproduction-only apparatus incapable of detecting a position in a data unrecorded area from detecting a position in the data unrecorded area and erroneously accessing the unrecorded area. The address information of a logical zone is utilized so as to search the latest VAT structure created at the end of the logical zone.
VATs 1363, 1369, and 1375 and VATICBs 164, 170, and 176 which are recorded in the VAT structure areas 1322, 1326, or 1330, respectively, each have a data structure in conformity with the UDF standards. With such a data structure, updating a file structure may be simplified in a write-once recording medium. A recording position of a file structure, such as a file entry, is pointed to by a virtual address in a virtual address space. A recording position on a disk is pointed to by a logical address in a logical address space. A correspondence between such a logical address and such a virtual address is stored in a VAT. A recording position for a VAT is pointed to by a VATICB provided at the end sector of an area in which data is recorded. A virtual address registered in a VAT is typically provided in each file management information in ascending order of registration to the VAT.
FIG. 15 is a block diagram illustrating a conventional information recording/reproducing apparatus 1500. The information recording/reproducing apparatus 1500 includes a system control unit 201, a memory circuit 202, an I/O bus 203, a magnetic optical disk device 204, and an optical disk drive device 205.
The system control unit 201 is realized using a microprocessor including a system control program and a memory. Specifically, the system control unit 201 includes a volume structure recording unit 211 for recording a volume structure, a volume structure reproducing unit 214 for reproducing a volume structure, a file structure recording unit 212 for recording a file structure, a file structure reproducing unit 215 for reproducing a file structure, a file recording unit 213 for recording file data, a file reproducing unit 216 for reproducing file data, a closing process unit 217 for instructing execution of a closing process, a VAT structure recording unit 281 for recording a VAT structure, and a VAT structure reproducing unit 282 for reproducing a VAT structure.
The memory circuit 202 includes a data memory 221 for operating or temporarily storing a volume structure, a file structure and a file, and a VAT structure memory 283 for operating or temporarily storing a VAT structure.
The optical disk drive device 205 includes a drive control unit 231, a memory circuit 232, an internal bus 233, a recording/reproducing unit 234, and an information recording medium 1300.
The drive control unit 231 is realized using a microprocessor including a drive control program and a memory. Specifically, the drive control unit 231 includes a border-out area recording unit 261, a physical format information reproducing unit 262, a physical format information recording unit 263, a state determination area recording unit 264, a border-in area recording unit 265, and a state determination area reproducing unit 267.
The memory circuit 232 includes a physical format information memory 266 used in operating or temporarily storing physical format information and a buffer memory 241 used in operating or temporarily storing data transferred to the optical disk drive device 205.
A closing process for a DVD-R disk will be described with reference to FIGS. 13, 15, 16, 17, and 18.
FIG. 16 is a data structure diagram of the information recording medium 1300 after a formatting process. FIG. 17 is a flowchart showing the closing process. FIG. 18 is a data structure diagram of the information recording medium 1300 after a closing process.
(S1701) The system control unit 201 instructs the optical disk drive device 205 to execute a closing process in accordance with a control program incorporated with the closing process unit 217.
The drive control unit 231 of the optical disk drive device 205 records data into a border-out area in accordance with a control program incorporated with the border-out area recording unit 261.
As to the operation of recording data to a border-out area, dummy data is recorded into the border-out area 1312, excluding the state determination area 1336, in the data structure diagram of FIG. 13, and dummy data is recorded in the border-out area 1310, excluding the state determination area 1334. For example, the dummy data is 00h.
(S1702) The drive control unit 231 reproduces data from the physical format information area 1332 provided in the lead-in area 108, in accordance with a control program incorporated with the physical format information reproducing unit 262.
When the physical format information area 1332 included in the lead-in area 108 is not unrecorded as shown in FIG. 13, the optical disk drive device 205 stores reproduced physical format information into the physical format information memory 266 of the memory circuit 232 and then executes step S1703 and thereafter.
When the physical format information area 1332 included in the lead-in area 108 is unrecorded (for example, see FIG. 16), data cannot be reproduced from the designated physical format information area 1332. In this case, the drive control unit 231 executes step S1705 and thereafter.
(S1703) The drive control unit 231 records 00h as dummy data into the state determination area 1334, which is unrecorded in FIG. 18, for example, in accordance with a control program incorporated with the state determination area recording unit 264. Thereby, the state determination area 1334 which is not unrecorded is created as shown in FIG. 13.
(S1704) In accordance with a control program incorporated with the border-in area recording unit 265, the drive control unit 231 creates physical format information and records the physical format information in the border-in area from the head of the unrecorded area 138 of FIG. 18 and thereafter, for example. In this recording operation, the border-in area 1311, including the physical format information area 1335, is recorded following the border-out area 1310 as shown in FIG. 13, for example.
(S1705) In accordance with a control program incorporated with the physical format information recording unit 265, the drive control unit 231 creates physical format information, and records the physical format information into the physical format information area 1332 included in the lead-in area 108.
When the above-described file recording and closing processes are executed with respect to the information recording medium 1300 having a formatted data structure shown in FIG. 16, a data structure shown in FIG. 18 is created in the information recording medium 1300. The address information of state determination areas are managed using a record management area (not shown) existing in an inner track inside a lead-in area.
When a file recording process is executed with respect to the information recording medium 1300 in which the data structure of FIG. 18 has been recorded, a Datafile shown in FIG. 14 and a file structure are additionally recorded. Further, when a closing process is executed in accordance with a procedure shown in FIG. 17, the data structure of FIG. 13 is created in the information recording medium 1300.
A procedure of reproducing an AVfile in accordance with the flowchart of FIG. 19 will be described with reference to the data structures of FIGS. 13 and 16 and the block diagram of FIG. 15.
(S1901) When the drive control unit 231 detects that a disk is inserted into the optical disk drive device 205, the drive control unit 231 actuates the recording/reproducing unit 234 in accordance with the control program incorporated with the physical format reproducing unit 262, and reproduces data recorded in the physical format information area 1332 of the lead-in area 108. Thereafter, the reproduced physical format information of the reproduced physical format information area 1332 is transferred to the physical format information memory 266.
(S1902) The drive control unit 231 retrieves the address information of a state determination area from the address information of a border-out area included in the physical format information retrieved in step S1901 or S1904 in accordance with the control program incorporated with the physical format information reproducing unit 262. Thereafter, the drive control unit 231 makes an attempt to reproduce data in the state determination area. In FIG. 13, the address information 1342 of the border-out area 1310 recorded in the physical format information area 1332 includes the address information of the state determination area 1334, and the address information 1346 of the border-out area 1312 recorded in the physical format information area 1335 includes the address information of the state determination area 1336.
When the state determination area designated by step S1902 is not unrecorded, step S1903 and thereafter are executed. When the state determination area designated by step S1902 is unrecorded, step S1905 and thereafter are executed.
(S1903) The drive control unit 231 executes reproduction of a border-in area included in the physical format information using the address information of the border-in area obtained in step S1901 or S1904, in accordance with the control program incorporated with the physical format information reproducing unit 262.
In FIG. 13, the address information 1343 of the border-in area recorded in the physical format area 1332 includes the address information of the border-in area 1310.
(S1904) The drive control unit 231 transfers the physical format information reproduced in step S1903 to the physical format information memory 266 of the memory circuit 232 in accordance with the control program incorporated with the physical format information reproducing unit 262.
(S1905) The drive control unit 231 refers to the latest physical format information stored in the physical format information memory 266 in accordance with the control program incorporated with the physical format information reproducing unit 262, and obtains the physical address of the end of the accessible area from the address information of the logical zone. In FIG. 13, since a second logical zone 116 is positioned at the end of the accessible area, the physical address of the end of the accessible area can be obtained based on the address information 144 of the second logical zone 116 recorded in the physical format information area 1335.
(S1906) The system control unit 201 instructs the optical disk drive device 205 to reproduce the volume structure area 118 in accordance with a control program incorporated with the volume structure reproducing unit 214.
The optical disk drive device 205 transfers the volume structure of the loaded information recording medium 1300 to the data memory 221 of the memory circuit 202. In this case, a volume structure as shown in FIG. 16 is read out.
Thereafter, the system control unit 201 obtains the address information of a file set descriptor 161 or a partition starting location 405 from the volume structure read out. Further, the system control unit 201 recognizes that a VAT structure is recorded, based on a type 1 partition map 407 registered at partition reference number 0 and a virtual partition map 408 registered at partition reference number 1.
(S1907) The system control unit 201 obtains the address information of a logical zone stored in the physical format information memory 266 of the optical disk drive device 205 as the physical address of the end of the accessible area, in accordance with a control program incorporated with the VAT structure reproducing unit 282. The system control unit 201 converts a physical address to a logical address. Further, the system control unit 201 instructs the optical disk drive device 205 to reproduce the VATICB 176 recorded at the end of the accessible area.
The optical disk drive device 205 reads and transfers the VATICB 176 to the VAT structure memory 283.
Thereafter, the system control unit 201 interprets the address information of the VAT included in the VATICB 176 read out, reads the VAT 1375 recorded in the VAT structure area 1330, and stores the VAT 1375 into the VAT structure memory 283.
(S1908) The system control unit 201 refers to a VAT entry, in which the file entry of a target file or directory is registered, using the VAT obtained in step S1907 when a target file and the management information thereof are managed using virtual addresses, in accordance with a control program incorporated with the file structure reproducing unit 215. Thereafter, the system control unit 201 converts a virtual address to a logical address and, using the file set descriptor 161 as a starting point, sequentially reads out a root directory file entry (FE) 174 and a root directory recorded therein, a directory (AV-Dir) FE 167 and a directory (AV-Dir) recorded therein, and an AVfile FE 166. Thereafter, the system control unit 201 obtains a position at which an AVfile is recorded.
(S1909) Finally, the system control unit 201 reads out an AVfile 165 in accordance with a control program incorporated with the file reproducing unit 216, thereby completing the file reproduction.
However, when an information reproducing apparatus, which does not have an ability to detect a position in an unrecorded area, obtains the end position of an accessible area from an information recording medium which records information in the above-described manner, the operation of reproducing information from a physical format information area and the operation of determining the recording state of a state determination area need to be alternately executed. Therefore, a time required for searching the end position of an accessible area is disadvantageously long.
Further, when an information reproducing apparatus searches a target file, both a volume structure and a VAT structure need to be searched. Therefore, the number of times data is recorded in the same area is not limited. When the information recording medium 1300 is used, a file search process needs to be more complicated and therefore a processing time is long, compared with when an information recording medium having a volume file structure which does not use an address conversion mechanism such as VAT is employed.
Furthermore, an AVfile may be used not only in a PC system including a large capacity memory and a high-speed processor, but also in a household AV apparatus including a limited capacity memory and a relatively poor performance processor. In this case, when an AVfile is recorded on a disk after a number of data files which are used only by PC systems has been recorded on the disk, the size of a VAT becomes large in proportion to the total number of recorded files or the management information thereof. Therefore, AVfiles are managed using virtual addresses having relatively large values. A household AV apparatus requires a larger capacity memory or a higher performance processor.